cobas b 221 <4> system 3337138001Recalls & reported problems

Summary

The FDA's MAUDE database contains 7 adverse event reports that list this exact device (DI 04015630018321), received between Oct 1, 2018 and Jul 14, 2025 — classified as 7 malfunctions.

The most frequently reported specific device problem is “Low Test Results” (3 reports).

1 FDA recall record name this device's identifier.

Reports come from manufacturers, hospitals and patients and are not verified by the FDA. A report does not prove the device caused the event, and counts can't be used to compare devices or estimate failure rates. How this data works · Data updated Oct 13, 2026.

Recalls naming this device

1. Feb 22, 2018Terminated

   The software responsible for starting scheduled AutoQC measurements (scheduler) will not activate.

   Z-1611-2018 · Root cause: Software design · FDA record ↗

Most reported problems

Recent adverse event reports

The 7 most recent of 7 reports, in the reporter's own words as published by the FDA.

• MalfunctionJul 14, 2025Incorrect, Inadequate or Imprecise Result or Readings; Incorrect, Inadequate or Imprecise Result or Readings

  WE RECEIVED AN ALLEGATION ABOUT DISCREPANT RESULTS FOR 1 PATIENT SAMPLE TESTED WITH THE IONIZED CALCIUM ASSAY ON A COBAS B 221 <4> SYSTEM. THE INITIAL RESULT WAS 1.52 MMOL/L. THE REPEAT RESULTS WERE 1.14 MMOL/L WHEN TESTED ON ANOTHER GASOMETER AND A COBAS C311 ANALYZER.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 22495219 ↗
• MalfunctionNov 4, 2024Low Test Results; Low Test Results

  THERE WAS AN ALLEGATION OF QUESTIONABLE GEN.2 ISE INDIRECT FOR K, NA, AND CL RESULTS FOR 1 PATIENT SAMPLE ON A COBAS B 221 BLOOD GAS ANALYZER. THIS MEDWATCH WILL COVER CL. REFER TO MEDWATCH WITH A1 PATIENT IDENTIFIER (B)(6) FOR INFORMATION ON THE K RESULTS AND MEDWATCH WITH A1 PATIENT IDENTIFIER (B)(6) FOR INFORMATION ON THE NA RESULTS. THE CUSTOMER QUESTIONED THE B 221 RESULTS AS THEY DID NOT MATCH THE PATIENT'S SERUM RESULTS FROM A C503 ANALYZER. THE PATIENT SAMPLES USED FOR THE ANALYZERS WERE REPORTEDLY COLLECTED AND PROCESSED AT THE SAME TIME. THE WHOLE BLOOD ARTERIAL SAMPLE ON THE B221 ANALYZER HAD A K RESULT OF 2.81 MMOL/L, A NA RESULT OF 129.7 MMOL/L, AND A CL RESULT OF 86.8 MMOL/L. A SERUM SAMPLE FROM THE PATIENT WAS TESTED ON A C503 ANALYZER AND THE K RESULT WAS 4.1 MMOL/L, A NA RESULT OF 137.5 MMOL/L, AND A CL RESULT OF 99.0 MMOL/L. THE REPEATED RESULTS WERE DEEMED CORRECT AS THE RESULTS CORRELATED WITH THE PATIENT'S CLINICAL PICTURE.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 20599165 ↗
• MalfunctionNov 4, 2024Low Test Results; Low Test Results

  THERE WAS AN ALLEGATION OF QUESTIONABLE GEN.2 ISE INDIRECT FOR K, NA, AND CL RESULTS FOR 1 PATIENT SAMPLE ON A COBAS B 221 BLOOD GAS ANALYZER. THIS MEDWATCH WILL COVER K. REFER TO MEDWATCH WITH A1 PATIENT IDENTIFIER (B)(6) FOR INFORMATION ON THE CL RESULTS AND MEDWATCH WITH A1 PATIENT IDENTIFIER (B)(6) FOR INFORMATION ON THE NA RESULTS. THE CUSTOMER QUESTIONED THE B 221 RESULTS AS THEY DID NOT MATCH THE PATIENT'S SERUM RESULTS FROM A C503 ANALYZER. THE PATIENT SAMPLES USED FOR THE ANALYZERS WERE REPORTEDLY COLLECTED AND PROCESSED AT THE SAME TIME. THE WHOLE BLOOD ARTERIAL SAMPLE ON THE B221 ANALYZER HAD A K RESULT OF 2.81 MMOL/L, A NA RESULT OF 129.7 MMOL/L, AND A CL RESULT OF 86.8 MMOL/L. A SERUM SAMPLE FROM THE PATIENT WAS TESTED ON A C503 ANALYZER AND THE K RESULT WAS 4.1 MMOL/L, A NA RESULT OF 137.5 MMOL/L, AND A CL RESULT OF 99.0 MMOL/L. THE REPEATED RESULTS WERE DEEMED CORRECT AS THE RESULTS CORRELATED WITH THE PATIENT'S CLINICAL PICTURE.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 20599143 ↗
• MalfunctionNov 4, 2024Low Test Results; Low Test Results

  THERE WAS AN ALLEGATION OF QUESTIONABLE GEN.2 ISE INDIRECT FOR K, NA, AND CL RESULTS FOR 1 PATIENT SAMPLE ON A COBAS B 221 BLOOD GAS ANALYZER. THIS MEDWATCH WILL COVER NA. REFER TO MEDWATCH WITH A1 PATIENT IDENTIFIER (B)(6) FOR INFORMATION ON THE CL RESULTS AND MEDWATCH WITH A1 PATIENT IDENTIFIER (B)(6) FOR INFORMATION ON THE K RESULTS. THE CUSTOMER QUESTIONED THE B 221 RESULTS AS THEY DID NOT MATCH THE PATIENT'S SERUM RESULTS FROM A C503 ANALYZER. THE PATIENT SAMPLES WERE REPORTEDLY COLLECTED AND PROCESSED AT THE SAME TIME. THE WHOLE BLOOD ARTERIAL SAMPLE ON THE B221 ANALYZER HAD A K RESULT OF 2.81 MMOL/L, A NA RESULT OF 129.7 MMOL/L, AND A CL RESULT OF 86.8 MMOL/L. A SERUM SAMPLE FROM THE PATIENT WAS TESTED ON A C503 ANALYZER AND THE K RESULT WAS 4.1 MMOL/L, A NA RESULT OF 137.5 MMOL/L, AND A CL RESULT OF 99.0 MMOL/L. THE REPEATED RESULTS WERE DEEMED CORRECT AS THE RESULTS CORRELATED WITH THE PATIENT'S CLINICAL PICTURE.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 20599113 ↗
• MalfunctionFeb 28, 2024Incorrect, Inadequate or Imprecise Result or Readings; Incorrect, Inadequate or Imprecise Result or Readings

  THE INITIAL REPORTER STATED THEY RECEIVED QUESTIONABLE RESULTS FOR ONE PATIENT SAMPLE TESTED ON A COBAS B 221 4 SYSTEM. RESULTS FOR THE FOLLOWING PARAMETERS WERE QUESTIONABLE: PCO2, PO2, PH, NA+, K+, CA2+, SO2, BE, P50. A FIRST SAMPLE WAS COLLECTED FROM THE PATIENT WAS TESTED ON THE ANALYZER AT 18:30, RESULTING IN THE FOLLOWING VALUES: PCO2 = 53.5 MMHG WITH A DATA FLAG PO2 = 74.0 MMHG WITH A DATA FLAG PH = 7.089 WITH A DATA FLAG NA+ = 131.5 MMOL/L WITH A DATA FLAG K+ = "OUT OF RANGE" (> 20.00 MMOL/L) WITH A DATA FLAG CA2+ = "OUT OF RANGE" (< 0.100 MMOL/L) WITH A DATA FLAG SO2 = 86.8 % WITH A DATA FLAG BE = -13.8 MMOL/L P50 = 37.6 MMHG THE RESULTS FROM THE FIRST SAMPLE SHOWED SEVERE RESPIRATORY ACIDOSIS BASED ON THE PH, PCO2, AND BE RESULTS. AS THE RESULTS DID NOT CORRELATE TO THE CLINICAL CONDITION OF THE PATIENT, A SECOND SAMPLE WAS COLLECTED FROM THE PATIENT AND TESTED ON THE ANALYZER. THE SECOND SAMPLE WAS TESTED AT 18:49 AND RESULTED IN THE FOLLOWING VALUES: PCO2 = 31.8 MMHG WITH A DATA FLAG PO2 = 44.3 MMHG WITH A DATA FLAG PH = 7.396 NA+ = 146.1 MMOL/L WITH A DATA FLAG K+ = 2.92 MMOL/L WITH A DATA FLAG CA2+ = 0.557 MMOL/L WITH A DATA FLAG SO2 = 75.9 % WITH A DATA FLAG BE = -5.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 18798005 ↗
• MalfunctionMar 1, 2023High Test Results; High Test Results

  THE INITIAL REPORTER QUESTIONED HIGH POTASSIUM (K) RESULTS FOR 5 PATIENTS TESTED ON TWO COBAS B 221 SYSTEMS. THE CUSTOMER IS QUESTIONING THE RESULTS FROM WHOLE BLOOD SAMPLES RUN ON THE B 221 INSTRUMENTS COMPARED TO RESULTS FROM PLASMA SAMPLES RUN ON NON-ROCHE INSTRUMENTS IN THE HOSPITAL LABORATORY. ARTERIAL BLOOD SAMPLES WERE OBTAINED FROM THE ARTERIAL LINE FOR RUNNING ON THE B 221 INSTRUMENTS. DUE TO THE HIGH K RESULTS, PLASMA SAMPLES WERE DRAWN AND SENT TO THE LABORATORY WHERE THE RESULTS WERE "NORMAL." REFER TO THE ATTACHED DATA FOR THE PATIENT RESULTS. NO QUESTIONABLE RESULTS WERE REPORTED OUTSIDE OF THE LABORATORY. THE CUSTOMER USED THE RESULTS FROM THE LABORATORY TO MONITOR THE PATIENT¿S CONDITION. THE K ELECTRODE LOT NUMBER WAS 21523447. THE EXPIRATION DATE WAS NOT PROVIDED. THE ELECTRODE WAS INSTALLED IN AUG-2022.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 16463803 ↗
• MalfunctionOct 1, 2018Non Reproducible Results; Non Reproducible Results

  THE CUSTOMER RECEIVED A QUESTIONABLE TOTAL HEMOGLOBIN (THB) RESULT FOR ONE PATIENT WITH A COBAS B 221 ANALYZER WHEN COMPARED TO A MEDICA INSTRUMENT. OF THE DATA PROVIDED, THERE WERE DISCREPANT RESULTS FOR THE THB AND PARTIAL PRESSURE OF OXYGEN (PO2) TESTS. THE THB RESULT FROM THE B 221 WAS 8.4 G/DL AND THE REPEAT RESULT FROM THE MEDICA INSTRUMENT WAS 11.7 G/DL. THE SAMPLE WAS REPEATED TWO MORE TIMES ON THE B 221 AND THE RESULTS WERE 13.5 G/DL AND 11.4 G/DL. THE PO2 RESULT FROM THE B 221 WAS 133.0 MMHG AND THE REPEAT RESULT FROM THE MEDICA INSTRUMENT WAS 133 MMHG. THERE WAS NO ALLEGATION OF AN ADVERSE EVENT. NO ERRONEOUS RESULTS WERE REPORTED OUTSIDE OF THE LABORATORY. THE CALIBRATION AND QC WERE ACCEPTABLE. THE SENSOR CARTRIDGE S1 LOT NUMBER WAS 21481005 WITH AN EXPIRATION DATE OF 02-MAR-2018 AND S2 LOT NUMBER WAS 21482019 WITH AN EXPIRATION DATE OF 11-NOV-2018.

  Patient problems: No Consequences Or Impact To Patient

  MAUDE report 7922864 ↗